The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 25, 2009
Filed:
Oct. 13, 2006
Applicant:
Hung-tsun Lin, Tainan, TW;
Inventor:
Hung-Tsun Lin, Tainan, TW;
Assignees:
ChipMOS Technologies (Bermuda) Ltd., Hamilton, BM;
ChipMOS Technologies Inc., Hsinchu, TW;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H01L 23/495 (2006.01);
U.S. Cl.
CPC ...
Abstract
A leadless leadframe has a plurality of bottom leads and a plurality of top soldering pads formed in different layers. After encapsulation and before solder ball placement, a half-etching process is performed to remove the bottom leads to make the top soldering pads electrically isolated, exposed and embedded in the encapsulant for solder ball placement where the soldering area of the top soldering pads is defined without the need of solder mask(s) to solve the diffusion of solder balls on the leads during reflow.